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Was MCAS part of 737 8 MAX MMEL list?
I think the answer to this question is no, because I cannot find it in the PDF, but I'd like a more expert opinion.
The reason I'm asking is the assumption that if it was, its malfunction could have been remedied by switching to the redundant "side" (perhaps as in pilot/copilot systems redundancy), along with a correctly functioning angle-of-attack sensor (the one that didn't break).

MCAS was not even in the pilot training program.

Well, the wings aren't in the MMEL either.

https://news.yahoo.com/ap-sources-boeing-changing-max-184231846.html -- I guess we can say I called it then

It does not appear that MCAS was in any of the maintenance documents. This was part of the issue with the Lion Air crash. On the previous flight with the accident aircraft, MCAS acted on the faulty sensor data, but the pilots used the trim cutout and completed the flight. They had no reason to suspect that a trim issue could be related to a faulty AOA sensor, so just the warnings for IAS and ATL DISAGREE and FEEL DIFF PRESS were logged for maintenance. As you noted, if they had known the connection, they might have diagnosed the true cause and either replaced the AOA sensor or MMEL'ed it. Instead they focused on the Air Data Module and elevator feel computer. It wasn't until a couple weeks after this crash that Boeing sent a message to operators describing MCAS.
It's also unlikely that the MMEL would have allowed MCAS to be completely disabled. This would have required extra documentation and possibly training for the pilots on how the plane would handle differently without it. This additional training is what MCAS was designed to avoid, and would have defeated the purpose of having it in the first place. Also, if it were that simple, it seems like they would have taken this step rather than grounding the entire fleet.

And speaking strictly about the redundancy of the MCAS system itself (where the "system" is MCAS and one Angle Attack Sensor connected to it) -- was there a redundancy (2 MCAS units, each connected to one side's Sensor) or not?

@youurayy. no, there was no redundancy at all. The system itself is only a protection, so it isn't required to be redundant. The problem was that it was not sufficiently secured against improper activation.

I understood the factual report not as saying MCAS wasn't mentioned at all, just that the troubleshooting checklists were insufficient. They even mentioned the AoA probe for at least one of the reported faults, but the mechanics had a “spurious success” on some of the checks that lead them to conclude they found and fixed the issue and end the maintenance without getting to test the AoA probe.

@JanHudec would you say that was the biggest fallacy of this case - not treating a system which can bring down the plane if it acts erroneously (not just due to a faulty AoA but e.g. the system itself misfiring, e.g. software or hardware fault in the MCAS logic itself) - as not needing redundancy?

@youurayy, no. The biggest fallacies were underestimating dangerousness of it's failure (fail-active due to bad input) and failure to realize impracticality of the only provided backup (the ET-302 did initially cut off the electric trim, but were unable to adjust it manually, so they turned the electric trim on again to try something else, which they didn't manage for reasons not yet fully analysed).


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Can we trade some efficiency to curb high-altitude emissions?
Considering our problematic issues,

Emissions at high altitude
Contrails
~10,000 premature deaths per year from airline emissions

This is an area of concern where it's worth asking some stupid questions.
What would happen if a hose was attached to the core/hot nozzle of a turbofan, diverted to storage on the body? Could it still be efficient 'enough' (assuming a highest possible bypass ratio) to compress and carry some of that carbon dioxide to the next airport?

@PerlDuck You don't need to capture all the air. You only need to capture the CO2. Assuming the jet fuel is 100% ethanol, C2H5OH + 3O2 = 2CO2 + 3H2O, that's a ratio of 1.7 CO2 to fuel, in terms of weight. Liquid CO2 actually has a higher density than jet fuel at room temperature. So still a hefty and unrealistic proposition, but not as crazy as initially believed.

@Jimmy Not sure if I can follow. This post says a B737-800 uses about 2,500 kg/hr of fuel (=1,250 per engine) during cruise. Does your calculation mean it emits 1.7 times 2,500 kg = 4,250 kg CO2 per hour?

@PerlDuck There's a set amount of fuel per aircraft. And yes, the aircraft would get heavier if we capture all the CO2 released. If we burn all the fuel stoichiometrically and assume a very optimistic fuel of 100% ethanol, the airplane will gain the weight of 1.7 times the fuel.

Context: "Globally, the team estimated that about 8,000 deaths a year result from pollution from planes at cruising altitude—about 35,000 feet (10,668 meters)—whereas about 2,000 deaths result from pollution emitted during takeoffs and landings."  and "Emissions from ships, for instance, kill an estimated 60,000 people a year, according to a 2007 study also published in Environmental Science & Technology."  CDC in US says "Cigarette smoking is responsible for more than 480,000 deaths per year in the United States, including more than 41,000 deaths resulting from secondhand smoke exposure."

"Nearly 1.25 million people die in road crashes each year, on average 3,287 deaths a day."  So sink all the ships, kill all the tobacco plants, and reduce the number of cars on the road - low hanging fruit vs trying to improve plane engines.

There's a fundamental problem. A jet engine performs work by expansion of the combustion products. Compressing the combustion products would require at least as much work as was provided by the expansion of the combustion products. Only an external combustion engine (for example, a steam engine) would work in this case.
A second problem is that the mass flow of the CO2 is more than three times higher than the mass flow of the fuel. Your plane would get heavier as you fly, and since the max landing weight of a typical plane is lower than the max takeoff weight, this will severely limit the aircraft range.
All in all, you can probably manage to make a purpose-built plane that fits the bill but I highly doubt it will have much usable payload if any at all.

This answer suggests the typical air mass flow of an airliner during cruise is around 100 kg per second per engine. Given a moderate bypass ratio of 8 this would yield 12.5 kg per second per engine. I'd assume the fuselage would simply blow up. Or, if some device was capable of compressing that amount of hot air within a second, the aircraft would gain weight at the same rate. That's 45 tons every hour. But maybe my calculation is too naive.

As mentioned in the comment section in OP, you don't need to capture all the air, just the CO2. Assuming the jet fuel is 100% ethanol, C2H5OH + 3O2 = 2CO2 + 3H2O, that's a ratio of 1.7 CO2 to fuel, in terms of weight. That is, if we burn stoichiometrically all the fuel (assuming ethanol), the plane will gain 0.7 times the weight of the fuel. Liquid CO2 actually has a higher density than jet fuel at room temperature. Obviously, this is still an impractical and uneconomical proposition, but not aphysical.

@PerlDuck, Even of these 12.5 kg, not everything is burned: jet engines burn a very lean mixture (due to temperature constraints), even if we consider just the core. It's better to calculate from fuel rather than air.

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Conversion of Pilot's license from Transport canada to FAA post minor heart attack
My husband got his license back in Canada but wants to move to the US, FAA is giving him a hard time in conversion. Is it even possible?

What specific problem is he having? Is it really his pilot license that is the problem, or is it actually his medical certificate?

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Is lift generated only by wings?
In modern aircraft is lift only generated by wings or can other parts of fuselage generate a significant amount as well, to the point it needs to be accounted for when designing a plane?

The fuselage, and any other surfaces that air is flowing over, will contribute to lift.  This was one of my interview questions when I joined Airbus in 2003!

To be picky, the word lift is normally used to refer to that portion of the total aerodynamic forces generated by a specified airfoil, (normally the main wing), which is normal (perpendicular), to the flight path. (the portion which is parallel top the flight is referred to as Drag).  The atmosphere is pressing on every single point on the surface of the aircraft, and generating a corresponding aerodynamic force at that point which is normal to the surface at that point, so this question is more a matter of semantics or definition than it is of physics.


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What are the dimensions of an approach plate plan view in nautical miles?
I am writing some software to work with approach plates on a website, but I cannot find the scale of the plan view.
I am trying to convert the position of a plane in latitude and longitude onto the approach plate and keep it to scale.
If I knew how many miles wide each plate was or tall, I could make this happen.
Thank you for the help!

You can easily work out the scale by measuring the distance from CUTIS to the runway threshold, which you know is 4,6NM

Related

FYI, what you're trying to do is called "georeferencing."
The scale for each plate is whatever is required to fit in all the relevant information without wasting space. Therefore, to properly geo-reference each plate, you will need to identify at least two points (e.g. CUTIS and CFVGK in this case), look up their lat/long in the published tables, and calculate the scale from there.
Note that some charts (more commonly SIDs and STARs than IAPs) are explicitly marked "NOT TO SCALE", which means this tactic can't work at all. And even some charts that are mostly to scale may have a few elements that aren't, usually transition fixes or navaids, marked by a double zigzag.

If the plate even has a scale. I believe I've seen some (but might have been SID/STAR plates only) that even explicitly mentioned they are “not to scale”.

Thank you. I have decided to define two fixes on the chart by clicking on it, then click the corners where I want the plane to show, then using math, I can make everything scale properly.

Just to amplify Jan Hudec's comment, the proportions, or ratios of distance, between points even on the same plate may be different.  This is what is meant by "not to scale".  They are close, but some portions may be compressed to fit it on the same page, while keeping other key areas large enough to be readable.  Think of the plate like a schematic, rather than a scale planform drawing.

@JanHudec Added.

There is no set universal scale, every plate is to scale but with different scales. Essentially, they scale the place to show the representation required to orient the pilot. When these plates are printed out they may be resized by software, so even saying X mm is 1.25NM won't work.
It sounds like you might want to superimpose a plane on the plan view, which is going to be challenging in many ways. Detecting scale is possible by measuring distance between CUTIS and CFVGK as others suggest, however that will be difficult to do programmatically because these are meant to be interpreted by squishy carbon units. Look at CUTIS:
CUTIS is the place where the squiggly line meets the thin line cutting across the arrow.

Programmatically determining exactly where to start your scale measurement will be extremely difficult, if you have it wrong by a few pixels that will translate into the wrong scale and your airplane symbol in the wrong place. If you solve that problem for this plate there's hundreds more that look different. There's so many edge cases you'd have to code around, it's unlikely you'd ever get them all.

If it were the case that there are an overwhelming number of edge cases, do you have a notion of how Avare and Foreflight both can show the plane's GPS location on the approach plate?


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Why do compressors constrict flow if this decreases pressure?
An axial compressor (and a ramjet intake, for that matter) is commonly depicted as decreasing the volume of air travelling through as we move closer to the combustion chamber. In axial compressors, either the rotor shaft / cone diameter expands the further along we go (Fig. 1), or the compressor housing squeezes in towards the shaft (Fig. 2).

Intuitively, this makes sense—if a gas is forced into a smaller volume, then it must have a higher pressure. Yet, doesn't the Venturi effect play a role here, as well? Shouldn't the static pressure decrease when the flow is constricted, as it is in these compressors? If so, why are they designed this way? Why not have the compressor diffuse air by increasing the volume instead?

Related: How does the size of each stage vary in a high pressure compressor?

The ramjet has supersonic flow until the narrowest section of the intake (and yes, the lower "M<1" points to the supersonic region), and pressure increases as the cross section decreases. In the narrowest point it has a straight shock and subsonic flow past it in which pressure increases further when the cross section widens. So a direct comparison of both converging geometries will be misleading.

Your understanding of Bernoulli's equation is correct, but the situation in a compressor is more complex, because energy is being added by the rotating blades.
When subsonic flow decreases in speed, and no energy is being added, the total pressure remains the same. This means the static pressure must increase,  because the LHS of Bernoulli's equation isn't changing:
Pt = Ps + 1/2 x rho x velocity ^ 2
But, in the compressor, the rotating blades are adding energy from the mechanical work they are doing on the fluid, and hence the total pressure increases. So, while the above equation still holds, the LHS is now increasing. The static pressure is then given by the isentropic compressible flow equation:
Pt = Ps x (1 + 0.2 x Mn^2).
When someone talks about "pressure" changing, they need to be very clear if they mean static or total pressure.
What the compressor is doing, is increasing the total pressure. Total values are the measure of energy in the flow. But because the Mach number stays about the same from compressor inlet to exit, the static pressure goes up also. But, this isn't really important, increasing the total pressure is the significant factor. Total values represent the energy content of a fluid, because as you can see in Bernoulli's equation, the energy content can be traded between the velocity term and the static term as the fluid speeds up or slows down, but this is just shifting energy from one form to another, it's not changing the total energy content.
As the air in the compressor is being compresssed, it actually needs less space, as your intuition would suggest. A complicating factor is the air temperature is also increasing, so it's not just the same volume of air at only a higher pressure. But, if the compressor expanded as you suggest, the velocity would decrease too much, and then the air flow over the rotor and stator blades would be too slow. This would cause them to loose their aerodynamic performance. The rotating blades would be ineffective in adding energy, and the blades would stall, as the rotational velocity would be too high in comparison with a low axial velocity. A high rotational velocity of the blades and low axial velocity of the air makes the angle of attack of the air on the blades increase. They stall like a wing on an aircraft going slow at a high angle of attack. When the air in the compressor stalls, it no longer wants to flow in the direction of increasing pressure towards the combustor. It reverses direction, and flames can even come out the front of the engine. Not good!

Subsonic flow increases in speed when the cross section narrows downstream. If no energy is added, pressure will decrease according to Bernoulli's law. However, in a compressor each stage will add energy to the flow, and this energy raises the static pressure. The narrowing is less to increase pressure and more to ensure proper flow speed.


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Does an aircraft with higher aspect ratio wings produce more wingtip vortices in a turn than one with lower aspect ratio wings?
The Ta-152H was well-known for having very high-aspect ratio wings: 8.94, if I'm not mistaken. Now, compare this to the P-51 which had, if I'm not mistaken, an aspect ratio of 5.86. Does this mean that in a turn the P-51 would produce more wingtip vortices than the Ta-152H?

The strength of a wingtip vortex depends on the span loading of the wing, so both weight and wingspan matter. A turn increases the apparent weight but does not change the comparison between aircraft. Aspect ratio is not a driver; it only matters as it relates to wingspan.
The P51 has a max takeoff weight of 15klb and a wingspan of 37ft, so 405lb/ft. The Ta152 has a max takeoff weight of 11.5klb and a wingspan of 47.4ft, so 242lb/ft. So at max takeoff weight the P51 would have a much stronger wingtip vortex.
Keep in mind that at high speed a wingtip vortex causes a very small amount of drag, so even if doubled it would still be overshadowed by many other factors. If you wanted to know which aircraft could out turn the other in a dogfight, wingtip vortex comparison will not provide the answer.

Vortices don't cause induced drag. Vortices are simply a byproduct of induced drag. They are how you can "tell" that induced drag is happening. The more induced drag a plane is producing, the more vortices it will have, but the vortices themselves are not the cause.

Also, when calculating wingloading, you should't use "max takeoff weight" because that number includes maximum amount of ordnance (such as bombs and external fuel tanks). When comparing two aircaft's dogfighting ability, it is much more useful to use "loaded weight", which is the weight of the aircraft fully loaded with fuel but without any external ordnance. The P-51D actually has a lower wingloading than the Ta 152H - 191kg/m^2 as opposed to the Ta 152H's 201kg/m^2 .

Easy to follow diagramFor two wings with the same area, the higher AR wing will produce LESS wingtip vortices simply because there is not as much area close to the wing tip that can be affected by the vortices.
The Ta-152H has a wing area of 253 ft^2 while the P-51 has a wing area of 235 ft^2
With those area's being so close together (7% apart) while the AR's are very different (35% apart) it would be a safe assumption to say the Ta-152H produces LESS wingtip vortices than the P-51.

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Do wingtip vortices cause a decrease in the lift component of aerodynamic force, and do planes need to pull more AoA to compensate?
So, from what I know about wingtip vortices, they shift the angle of the relative airflow to where the effective angle of attack of the airfoil is lowered. Since the aerodynamic force is always perpendicular to the relative airflow, the aerodynamic force is also shifted and now has a backwards-facing component to it, which we call induced drag. Now, my question is, just looking at the way the vectors point, the tilting of the aerodynamic force backwards means that, while there is a greater backwards facing component, the upwards facing component (what we call lift) is decreased, right? So we can say that the vortices shift the aerodynamic force in a way so that the induced drag increases, but the lift decreases, right? And, if that is the case, then wouldn't the aircraft then need to pull an even greater AoA to compensate for that lost lift, which in turn would create even more pressure differential, which would then increase vortices even more? Then even more AoA would be needed, and so on... Then this cycle would go on until the aircraft bled all its speed... Obviously, that isn't the case and there isn't a snowball effect in real life? So is my fundamental understanding of vortices and induced drag off?

What you know about wingtip vortices is what can be found all over the Internet, but it is not really true. It is like saying that wet streets cause rain.
Your way of explaining things confuses cause and effect. The vortex is the effect but not the cause of drag-creating flow. And lift-creating flow, by the way. But nobody claims that the tip vortex is the source of lift, which is equally false and uses the exact same logic.
Wingtip vortices are just the tip of a full vortex sheet which leaves the wing. This vortex sheet is the consequence of the wing accelerating air downwards. Now instead of repeating myself all over again, please allow me to point you to the many other answers which explain what is going on:

This answer explains in detail how lift is created and how the downward acceleration of air is accomplished.
This answer goes into the formation of the wake and the wingtip vortices.
This answer shows why more wingspan reduces induced drag. It matters little whether the wingtips are turned up, down or continue straight: A larger wingspan reduces induced drag.

You will find that your picture of a tilted-back aerodynamic force vector is correct, and indeed will a narrower wing experience larger tilting for the same lift. Also, to achieve the same lift, a narrower wing needs more angle of attack and will create more induced drag. You are right again here, but instead of an ever increasing snowball effect, drag is just growing with the square of lift when the angle of attack is increased.
Ideally, all aircraft would have infinite wing span. But that would drive wing weight up a lot, so the designers settle for some compromise where the wing creates the least drag for a given net lift (total lift minus the lift needed to carry the wing).

Now to the questions in the comments:

so the point of a higher AR ratio wing isn't to reduce vortices... It's simply to reduce the required AoA that is needed?

The point of a higher AR (more precise: More span per lift) is to involve more air in the creation of lift. This reduces the strength of the bound vortex, so indirectly it is about vortex reduction. The AoA reduction is not an issue here - in inviscid 2D flow an airfoil produces no drag, regardless of AoA. What does produce drag is the vortex flow field when span is limited.

the reduction in vortices is simply how we see that it is working, per se?

Yes, reduced bound vortex strength results in reduced wake vortex strength.

why do [designers] also care about the chord?

For that, allow me to refer you to this answer, and maybe this, too.

Is it correct to say that we can measure the energy an aircraft loses due to induced drag by measuring the energy in the vortices?

Yes. But measuring the vortex strength is harder than measuring the downwash angle over span, which gives the same result. For viscous losses this is indeed a practical way of measuring drag by use of a wake rake (see the answers to this question for more).

OK, so the point of a higher AR ratio wing isn't to reduce vortices... It's simply to reduce the required AoA that is needed? And the reduction in vortices is simply how we see that it is working, per say? It's just a byproduct of less AoA?

Another question if you don't mind: If wingspan is the important factor here (since a larger wingspan affects a larger amount of air thus requires less AoA) then why do engineers also care about wing loading, i.e. why do they also care about the chord? Shouldn't they only be focused on the wingspan and not the total area of the wing?

Thanks! You've answered a bunch of questions I've had. I can't tell you how confused I was by scouring the internet and finding a bunch of misleading, counterintuitive, and contradicting explanations of induced drag and vortices. Now I believe it all makes sense (well, as much as it can make sense without actually knowing all the mathematics. However, I do have one more question, if you don't mind. Is it correct to say that we can measure the energy an aircraft looses due to induced drag by measuring the energy in the vortices?

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What's the relation between speed of an aircraft and takeoff distance?
I'm making a tool that when given : weight of aircraft , takeoff speed , runway length and some other parameters , it analysis the takeoff performance and states whether using the brakes now is safe or not . So I'm looking for a mathematical relation between the takeoff speed and the takeoff distance to use it in my code . Based on the given speed I want to determine whether the runway length will be enough or there will be a hazard . Is there any mathematical formula for calculating the takeoff distance using takeoff speed and weight ?? or how do people calculate that ? I need any method .
Any help is appreciated . Thanks

Takeoff distance can be obtained analytically by integrating the speed of the aircraft between $v_0$ and $v_{TO}$, with the snag being that the acceleration is dependent on $v$ through the thrust and drag terms. You cannot obtain the distance using only the weight and takeoff speed, you need to know the acceleration. In practice the values are tabulated.

Also depends if this is a one-engine airplane or multiengine.

I think your question is regarding new aircraft under design and not for existing planes?
The dynamics of ground roll/stopping is governed by one equation:
$$m\ddot{x}=T-D-\mu(L-mg)$$
where $T$ is thrust, $D$ is drag, $\mu$ is friction coefficient, $L$ is lift, $m$ is mass and $g$ is gravitational accel. Since thrust, drag and lift are a function of airspeed (and spoilers + brakes + thrust reverser should abort occur), the most naive way is just to numerically integrate the equation twice to get the distance at time.
That being said, don't forget that takeoff distance and accelerate-stop distance must be considered with all engines operating and with the critical engine failed. $V_1$, assuming not limited by controllability, should be selected such that the two distances balance. Also keep in mind that a good portion of takeoff distance is rotating and accelerating to $V_2$ before 35ft with the critical engine failed. The previous equation does not account for that portion.

Friction linear on perpendicular force (weight minus lift) I could understand for the wheels sliding against the ground. But given the wheels are turning with the ground and the brakes are generating the friction, how does the weight come into play?

@Jeffrey Not sure I understand your question. There is still non-zero rolling friction and braking generates sliding/static friction depending on the application of the brakes/anti-skid. Mu is just a phenomenological agglomerate of the effect.

Yeah, but then the weigh-lift is not the correct force to use. The correct force is hydraulic pressure on the brake pad. The friction part you state works as a upper-bound, though

@Jeffrey It depends on the fidelity to which you want to model the system. Generally, with a good anti-skid, there's a relatively constant braking coefficient (mu) for the given runway condition. This is usually sufficient for performance calculations, especially at the early stages.

Generally, the performance charts in the POH are used. You'd have to turn those into account. Runway length, weight, temperature, wind. When I flew a 100HP C150, there were days I couldn't take off with full tanks and my instructor on warm days out of the 1686 foot strip with obstructions where I was based. Even when I moved up to a 180HP C177, there were some trips where I met the family at a longer strip when we had full tanks and were taking a lot of baggage for a family vacation.
For bigger passenger planes, there where days last summer in AZ I think that some planes coudl only depart first thing in the morning because temps got too hot for safe takeoffs, engines couldn't make enough power in the high heat that was occurring.
So you'll need to go plane by plane to create a performance data equation.

You may start by building your model based on a plane with tricycle gear (not a tail dragger) accelerating from standing start Vo to rotation speed Vr. This will make it much easier, as the pitch of the plane will not change.
Acceleration is based on thrust acting on a given mass (a=f/m).  In a vacuum you would be done.  Not here.  Drag begins acting on the aircraft as soon as it moves.  Engine rpm may increase as airflow unloads the prop.  Pounds of drag must be subtracted from pounds of thrust to yield acceleration at a given speed.
Full scale wind tunnel thrust and drag data from Vo up to Vr speed would generate an acceleration curve for various speeds (in the old days we would reach for log graph paper to try and make it a straight line).
So, even with standard pressure and temperature it is complicated, so one must go and do it the old fashioned way, one data point at a time. As stated in comments, this gives a tabulated chart.
From this chart mathematical extrapolations can be derived, graphs can be drawn,
and formulas developed.  These formulas can be refined with still more testing.
Once these are reasonably accurate, a computer program can be written that will happily crunch combinations of thrust, weight, and drag to generate a take off distance and speed based on the acceleration curve.
Calculations for various flap settings, atmospheric conditions, precipitation, headwinds/tailwinds, and runway surface conditions could be programmed in as well.
But because of the critical nature of take-off distance, thorough validation of published values is a must.


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While flying having trouble estimating how far I am from Airport
When approaching an uncontrolled airport especially, standard procedure demands to make the first call 10 miles out announcing my location, entry procedure, etc. and then more calls at 5 miles, 2 miles, etc. I find myself having a hard time estimating how far I am from an airport so I can announce my position. The same applies when I'm asked to report a 8 mile final in a controlled airport. I'm curious how others do it and if there's a more reliable way to judge distance from an airport. Thanks.

Gets better with practice.

On a US Sectional, the length of the shorter part of your thumb, where the fingernail is, is about 10 nautical miles (check yours against the chart on the bottom). If you are keeping track of where you are along your pre-drawn course line, you quickly check your thumb against the sectional for a distance.

I guess this is a rule of thumb?

My GPS tells me the distance.
Otherwise, my experience says:

15 miles (and about 3,000 AGL) is where I'm not entirely sure I have the airport picked out.
10 miles is where I can see the airport, but not pick out specific details and airplanes.
5 miles is where I can see the airport clearly, and setup for the centerline.

Yup, wanted to know how people do this w/o a GPS. I was also think using the scale in a terminal map and translating that to actual distance to get an estimate.


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If the previous 100 hour was overflown but not for hire, is the time still subtracted from the next 100 hour?
A rental plane at a local FBO had an annual inspection at 2345 hours on the Hobbs. The next 100 hour inspection wasn't completed until 2450.
If the current hobbs time shows 2547, would it be legal to take the airplane for a 2 hour flight lesson with an instructor?
Also, does the legality of this situation change depending on whether the 5 hours between 2445 and 2450 was with an instructor or not?

CFR 91.409 (b) applies here:

Except as provided in paragraph (c) of this section, no person may operate an aircraft carrying any person (other than a crewmember) for hire, and no person may give flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours of time in service the aircraft has received an annual or 100-hour inspection and been approved for return to service in accordance with part 43 of this chapter or has received an inspection for the issuance of an airworthiness certificate in accordance with part 21 of this chapter. The 100-hour limitation may be exceeded by not more than 10 hours while en route to reach a place where the inspection can be done. The excess time used to reach a place where the inspection can be done must be included in computing the next 100 hours of time in service.

Since the aircraft went 5 hours over on the last inspection cycle you must take this into account.  Therefore the 100 hour should have been performed at 2545 hours.  The airplane is overdue, and can only be flown enroute to a location for inspection.

According to FAR 91.409 b, the 100 hours can be overflown by ten hours in order to fly the plane to a place where the inspection can be performed, but this time must be included in the next 100 hour period.
If the five hours over the designated 100 hour time limit was for hire (ie not flying the airplane to somewhere the inspection could be performed) then they were technically illegal. And no, that wouldn't change the fact that you must count those hours in the current 100 hour cycle.


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Landing without explicit permission
What will happen if civilian ATC suddenly sees unknown plane which request landing due to emergency.
Can ATC just forbid such land? If yes, what they do?
What if it's foreign military plane?

Not sure what you mean by "unknown plane", because civilian towers often don't know anything about the planes that request to land there. Also even if the plane didn't request landing clearance they wouldn't try to stop it because it's possible that the plane's radio isn't working.

ATC can't "forbid" anything really, they certainly can't enforce it - there is physically no way to stop an aircraft landing. Notwithstanding hostile intentions, in any sort of emergency ATC, civilian or military, will do everything they can to aid the safe landing of an aircraft in distress.
Remember, ATC are not "in charge", they are there to facilitate the safe, orderly flow of aircraft within the rules set out.
As for what would happen once the aircraft is on the ground, that's a whole other matter not really to do with ATC at all.

There is the incident of Viktor Belenko who defected to the West and landed a MiG-25 at Hakodate, Japan.  There is even a book ("MiG Pilot: The Final Escape of Lieutenant Belenko") about his life and defection.  As I remember, his radio didn't handle western ATC frequencies, so he couldn't even declare an emergency.  He had a close call with a airliner who was taking off, but was able to land safely.
Stopping it would require a surface-to-air missile or something roughly equivalent.

A scenario where a foreign military plane would enter the airspace of a sovereign state without its consent is a bit far fetched, although not entirely impossible.
Should the said plane declare an emergency, the ATC most likely would not, and more importantly could not prevent a landing. if the airforce and/or air defences of the state in question disagreed with the landing intentions, they could intervene and transform the landing into a crash.


text:
Sightseeing in a class Bravo airspace?
I went to go fly around DFW today, wanted to do some sight see of the city and such. When I got in the air I contacted approach to get VFR flight following and was going to remain outside of the class B airspace anyways for most of it. When requesting to go closer I was told I would need to have an LOA with KDAL (Dallas-Lovefield), which I did not so I remained outside the Bravo, what is an LOA and or how is the best way to be inside the class B for sight seeing?

For the question in the title: https://aviation.stackexchange.com/questions/6/how-do-i-sightsee-in-a-class-bravo-airspace?rq=1  (Doesn't help with your specific situation.)

Letters of Authorization (LOAs) are authorization to conduct various types of commercial flights in certain airspace.  They are defined and governed by FAA Order 8900.1 and can be obtained from the regional Flight Standards District Office (FSDO) for that area.  It is not necessary for non-commercial general aviation operations.  I suspect (and I don't know the full details as to how you contacted Ft Worth Approach) that the controller thought you were a commercial operation requesting to start doing some sightseeing over the Dallas Ft. Worth Area without having done this paperwork.
Usually as a GA pilot, you can simply contact approach control for a Class B airspace and request a transition through Class Bravo.  This request may or may not be granted depending on commercial traffic congestion that day, etc.  They may also want you to stick to existing VFR traffic transition routes and not deviate from that.  Class B, as a general rule, is not very accommodating for sightseeing and other leisure flying.

Thank you where can I find the VFR traffic transitions? And can a GA pilot option an LOA so they are able to conduct these types of operations.

@iqueqiorio, if you don't know how to get a clearance I would suggest you get some instructor time on the ground to go over it. You want to make sure you get it right or you could lose your ticket.

VFR transition routes are listed on the backs of terminal area charts, if they are published, or check the chart supplements for that region.

Most TRACONs have canned "tours" you can request; ask a local CFI/FBO or phone TRACON yourself for a list. They might approve minor deviations in the air, depending on traffic, but it's unlikely they'll approve anything novel.


text:
Propeller air displacement
I was thinking about propeller design just now and it came to mind that, theoretically, the air displaced by the propeller after every rotation might not be able to "flow back" into the area "served" by the propeller, resulting in a propeller surge, I guess you would call it.
Does this generally happen, is this accounted for in general or only in very detailed calculations or basically not at all? Does it have a name?
Edit: At high RPMs, of course.

I hope I'm understanding your question correctly. Propeller cavitation is the effect of airflow caused by a low pressure zone the propeller generates when it displaces the air. Here is a good video describing it's effect on submarine propellers: https://www.youtube.com/watch?v=ON_irzFAU9c

I think what she is actually talking about is blade stall, since the prop is just  a spinning wing. Mostly a problem for fixed pitch propellers where the static thrust is below the prop's potential because some of the blade is stalled, and thrust builds as the airplane accelerates and blade angle of attack goes down.   I would think this is largely addressed by variable pitch/constant speed propellers which keep blade AOA closer to optimum most of the time.

Perhaps you mean something like the 'vortex ring state', that sometimes appears in helicopter rotors, causing an abrupt loss of thrust.

It was really just a blade stall actually, thinking about it, you're right @John K, though I guess the "disruption of airflow" is a kind of special case here!
What I was wondering about is: Are blade stalls only accounted for in detailed foil-making for propellers or is it even in superficial calculations/designs a necessary or widespread variable?

@xxavier  a vortex ring state requires a high descent rate in a helicopter (it's not the same as settling with power) something like 500 fpm or more.  A  propeller would have to be going backward.

@John K  I know... That's why I wrote 'something like'... However, that can indeed happen in convertiplanes, where the propellers/rotors may have also vertical thrust, and can be immersed in their own wake, while in a descent...

Julie M I would say that blade stall is one of the primary considerations just as wing stall would be with an airplane.  You are bounded by two limits - blade stall at high AOA and shock wave formation at high speed (lots of propellers exceed Mach at the tip at redline RPM; that's the piecing blat you hear on takeoff sometimes).  Challenge for designers is the huge speed variation from root to tip. Even with a variable pitch prop, you have to figure out airfoil section and incidence (relative twist) at each point going from root to tip taking into account both stall, and Mach near the tips.


text:
How come diverterless supersonic inlets haven't been discovered much earlier?
DSI's seem like such an absolutely elegant solution to a problem that has, so far, been solved in a truly overly complicated way.
So, if I'm not missing out on some important small speck of knowledge that complicates DSI's way, way more than being a bump to subsonicize air (of course a slight bit more than that, but you get the idea), then I feel like it is justified for me to get the well-known "this stuff is way too easy to be true"-feeling.
To actually ask the question: Are DSI's really as easy of a solution as they seem right now?

I guess you need some serious computing power to calculate it.

Probably for the same reason it took so long to go from a jar of jelly to a squeezable plastic container with a thin slit lid for spreading. It's really not all that obvious until someone thinks of it, and once one person thinks of it everyone else says "That's so obvious! Why didn't I think of that???".

Designing a DSI inlet is not so simple. It required CFD, a field which had existed for a while but was still viewed with some suspicion in the 1990s. CFD is computationally intensive, so the field has benefited from the massive advances in computing power since the invention of the transistor.

The DSI traces its roots to work done by Lockheed Martin engineers in the early 1990s as part of an independent research and development project called the Advanced Propulsion Integration project. The concept was developed and refined with Lockheed Martin-proprietary computer modeling tools made possible by advances in Computational Fluid Dynamics, or CFD. CFD is the science of determining a numerical solution to the governing equations of fluid flow and advancing this solution through space or time to describe a complete flow field of interest—in this case, the flow field of a fighter forebody, inlet, and inlet duct.


text:
Where is the F-4 Phantom II's flap lever?
I'm trying to fly this fighter for the first time in X-Plane 11 but I can't seem to find the flap lever in the cockpit. Where is it on the real plane?

Comments are not for extended discussion; this conversation has been moved to chat.


text:
What is TOGA LK in Airbus 320? How to come out of TOGA LK?
What is TOGA LK in Airbus 320? How to come out of TOGA LK? I see it comes in Windshear Escape Manoeuvre. How is it related to Alpha Floor.

TOGA LK is short for Takeoff Go-around (Power) Locked.
Which means, due to some kind of situation (e.g. reaching Alpha Floor), the aircraft decided it'd be a good idea to spool the engines up to maximum thrust.
It will remain at that power setting no matter what the thrust levers were set to before the TOGA LK state was applied by the aircraft, hence "locked". Only once you move the thrust levers after TOGA LK was activated and turn off the A/THR, the aircraft will reduce the thrust to whatever is set on the thrust levers.

I'll try to get my point across in a better way, one sec...

A reference would help as well.

TOGA LK (TOGA thrust locked) is displayed on the FMA after an activation of the ALPHA FLOOR protection when the activation conditions are no longer fulfilled (A FLOOR is displayed during the ALPHA FLOOR condition). The idea is that the thrust does not automatically reduce again after ALPHA FLOOR because this could result in a situation where the speed decreases again. The procedure to get out of TOGA LK is described in the FCTM (Flight Crew Training Manual):

ALPHA FLOOR
When the aircraft’s angle-of-attack goes beyond the ALPHA FLOOR threshold, this
means that the aircraft has decelerated significantly (below ALPHA PROT speed):
A/THR activates automatically and orders TOGA thrust, regardless of the thrust lever
position.
The example below illustrates that:

The aircraft is in descent with the thrust levers manually set to IDLE.
The aircraft decelerates, during manual flight with the FD off, as indicated on the FMA.

When the speed decreases, so that the angle-of-attack reaches the ALPHA FLOOR
threshold, A/THR activates and orders TOGA thrust, despite the fact that the thrust
levers are at IDLE.
When the aircraft accelerates again, the angle-of-attack drops below the ALPHA
FLOOR threshold. TOGA thrust is maintained or locked. This enables the flight crew
to reduce thrust, as necessary. TOGA LK appears on the FMA to indicate that TOGA
thrust is locked. The desired thrust can only be recovered by setting A/THR to off,
with the instinctive disconnect pushbutton.
ALPHA floor is available, when the flight controls are in NORMAL LAW, from liftoff
to 100 ft RA at landing. It is inhibited in some cases of engine failure.

(Airbus A320 FCTM - Operational Philosophy - AP / FD / ATHR, emphasis mine)
The TOGA LK state is not necessarily linked to a Windshear, but since ALPHA FLOOR is part of the Windshear escape strategy, it can certainly appear in this context. The FCTM describes the following strategy to escape a Windshear:

There are three efficient tools to assist the flight crew to escape:

The alpha floor protection
the SRS AP/FD pitch law
The high angle of attack protection

When the alpha floor protection is triggered, the A/THR triggers TOGA on all
engines. The FMA displays A FLOOR, that changes to TOGA LK, when the
aircraft angle-of-attack has decreased. TOGA/LK can only be deselected by
turning the A/THR off.
The SRS pitch mode ensures the best aircraft climb performance. Therefore, the
procedure requests following the SRS pitch bar and possibly full aft stick, in order
to follow the SRS orders and minimize the loss of height.
The high angle-of-attack protection enables the PF to safely pull full aft stick, if
needed, in order to follow the SRS pitch order, or to rapidly counteract a down
movement. This provides maximum lift and minimum drag, by automatically
retracting the speed brakes, if they are extended.

(A320 FCTM - Supplementary Information - Adverse Weather, emphasis mine)

A floor is a protection activated in Airbus when the speed drops below VA-prot. The FAC then sends signal to auto thrust system to set max thrust available irrespective of the thrust lever position. The thrust gets locked in this position.
To get out of A floor, you reduce angle of attack. The speeds increases now rapidly as max thrust is set.
If you don’t reduce thrust quickly, you may breach flap limiting speed or Vmo.
To get out of TOGA LOCK

Set thrust lever to TOGA
Disconnect auto thrust by using instinctive push buttons on thrust levers
Set thrust levers to Climb
Rearm autothrust system by pushing auto thrust push button on FCU.


text:
Eye requirements for private pilots license in the US?
In the next couple of years, I would like to work on obtaining a private pilot license with the goal of eventually getting my own plane. But my eyesight isn't that great in my left eye.
As a kid, I was born with amblyopia/strabismus. Did eye surgery as a kid which didn't really correct the vision. Though my eyes appear normal, my right is 20/20 and my left is 20/80/100. I should also clarify that glasses cannot remedy the left eye in terms of acuity.
So my question is will I be able to get a license? If not, that's fine, but I'd like to know so I can focus my energy and interests elsewhere.
Thanks.

The standard vision requirements are also given in this answer.

The guidance for vision requirements are listed here.  Basically for a private pilot distant vision must be 20/40, near vision 20/40, and no requirement for intermediate vision.  The website says

In each eye separately with or without correction

I interpret that to mean that your left eye must be 20/40 or better.  However the final authority on this would be the FAA approved medical examiner and it wouldn't hurt to go ahead and schedule a FAA Type III medical examination and see what the doctor has to say.  Unfortunately your insurance won't cover the exam and you would have to pay somewhere around $150 for it.  However you will have a better understanding of what your options are if you want to pursue flying.  Sometimes a license can be granted but with restrictions if a pilot has a medical condition.
I hope you will be able to pursue flying and wish you the best of luck!


text:
Under what circumstances is the Aircraft 'Stability-Axis' system used in either design or analysis of aircraft?
I understand the definition of aircraft 'Stability-Axis', but I am unsure as to the circumstances in which forces or moments would be expressed in this axis system. Is there a convention?
What I do know:

It is useful for wind tunnel analysis, where forces and moments are
often calculated from a force balance fixed to the aircraft that is
invariant with model Alpha and Yaws with the aircraft for variations in Beta. (Obviously depending on windtunnel/model set-up).
It can be used as an approximation for Wind-Axis is Alpha is known and Beta is assumed to be small.

What I don't know:

Many things
Why Stability-Axis is used instead of Body-Axis or Wind-Axis?

Body-axis is used to construct the equations of motion and express the aircraft angular velocity and Euler attitudes. By conventional, it is defined such that the x-axis is aligned with the nose and the x-z plane is the plane of symmetry.
Stability-axis, whose x-axis is aligned with the longitudinal incidence of the flow against the body-axis, is used to express aerodynamic data, which are derived from semi-analytical methods (e.g. DATCOM, ESDU), computational methods (e.g. vortex-lattice methods, Navier-Stokes), wind tunnel testing, or full flight data.
Stability-axis is used for aerodynamics because lift and drag are conveniently aligned with the axes. And as the OP alluded to, it is much easier to rotate the aircraft against the wind tunnel balances, than to rotate the flow against the test model.
Wind-axis has its x-axis aligned exactly with the flow velocity vector. It's not really used anywhere. We don't use wind axis because it breaks the x-z symmetry and makes things more complicated than need be. It does not offer any additional benefit than stability-axis.

Image from: https://www.mathematica-journal.com/issue/v8i2/features/codegeneration/contents/html/Links/index_lnk_3.html

Thank you for your answer! That has helped to explain; the symmetry argument definitely makes sense. A further query about the image you posted - lift and drag would conventionally be given in stability or wind axis system. Why is the wind/stability axis indicated to be positive nose-forwards, when positive drag is aft (and also lift, down)?

@William Drag is negative of the "forward" motion, and lift is negative of the "downward" motion, in the stability axis. That's just the convention agreed upon by the industry.


text:
What are the expected vibration frequencies in a co-axial rotor system with contra-rotating propellers?
I am trying to understand the frequency spectrum of a co-axial rotor system. Form now i have a RC helicopter with two sets of three gear systems arranged in parallel, The number of teeth are 7,23,27) respectively. The 2 input dc motors are running at 35K RPM which runs the rotors at approximately 2800 RPM because of the total gear ratio 12.47.
What I understand the frequency spectrum should have
-6 peaks of individual gears at there respective rpm's.
-2 peaks of Gear Mesh Frequency
-2 peaks of blade pass frequencies (rotor have 2 blades each total 4 blades in the RC helicopter.
Is there anything I am missing in this?


text:
Do any private charter schools sponsor your pilot school tuition?
Do any US or European private charters pay for your jet pilot school in exchange for contract pilot service?

I highly doubt it. Jet training is expensive, very expensive. They still have to pay you afterwards, so they aren't getting a lot (they can't make you an indentured servant). There are a couple big commercial operators that do this, like Lufthansa but the number of "slots" available is very limited and there is a huge demand for it, so they only take unusually qualified individuals, and the "free" school is structured as a deferred loan that you pay back during employment.

thank you. I will step with that info and pay my bills from the first rung on the ladder.


text:
Close Runway 16/34 from one direction
Let's say Runway 16/34 used direction 16 for arrival and 34 for departure. Can the runway close 16 (arrival direction) and still working in 34 for departure?

Both arrival and departure always happen in the same direction. Either both use 16 or both use 34 but never both directions at the same time.

@PerlDuck you mean it's ok to close one direction and use the other for arrival and departure?

It's not only "ok", it's mandatory. But of course a runway can be restricted to take-off only or landing only, like runway 18 in Frankfurt, for example (only take off), or 07L/25R (landing only).

@PerlDuck. Thank you, So, It's not mandatory to close the two directions of the runway when one direction was closed.

@PerlDuck Not really true. Some airports have one way in/one way out runways for various reasons (terrain, noise). And runways are commonly used in changing directions depending on the direction of the flight, to save flight time

@Bark Please clarify what you mean by closing the runway. Obviously, if the runway closes because there is a hole in the pavement, it doesn't matter which direction - the full runway is closed.

@J.Hougaard You are referring to e.g. Lukla airport (kinda "dead end" runway due to a mountain on one end), aren't you? Of course you are right, but I just wanted to stick to the ordinary ones.

@J.Hougaard I think you are right it depends on the reason or obstacles if it's for construction or if there is an accident in the on any runway direction the full runway will be closed. But is there any example to close one direction only in the normal runway?

I think your premises are wrong. If an airport has a runway 16/34 then either both landings and departures take place in direction 16 (runway 16 is open) or both take place in direction 34.
In most cases both directions are not used at the same time. Which direction is chosen usually depends on the current wind direction so planes depart and arrive with headwind (not tailwind). Which one is open (16 or 34) can change from day to day, even during a day. Usually one of the directions is used most of the time because the wind usually comes from a certain direction. For example, London Heathrow has two parallel runways and in approx. 70 % of the time the wind comes from the west (westerly operation). Hence, they use runways 27L and 27R most of the time for both arrivals and departures.
There are, however, runways that are restricted to either take-off or landings, like runway 18 in Frankfurt, for example (only for take off), or 07L/25R (only for landing). But again, 07L/25R means: either all planes land in direction (on runway) 07 (towards the east) or all land in direction (on runway) 25 (towards the west).
See also:

What determines in which direction a runway is used?
Why is tailwind during final approach and landing so dangerous?

I know we can't use both directions at the same time. What I mean by runway closure here if one direction closed for any reason or obstacles. Is it necessary to close the full runway (both directions 16/34 no flight landed or take-off from this runway) or just close the direction where are the obstacles and use the other direction?

@Bakr I'd say "it depends". If 16 is chosen based on the wind direction but cannot be used because of an obstacle that suddenly popped up, it depends on how strong the wind is. An aircraft cannot take off/land with strong tailwind because it then would need a longer runway to gain/lose airspeed and lift. But the runway's length is limited. So with calm wind conditions they might change the runway and switch to 34. If the wind blows faster from behind, switching direction is not feasable and the whole runway would be closed.

@PerlDuck While the 'one direction at a time' policy makes sense at most airports, there are some that routinely takeoff and land in opposite directions. They are not high volume airports (as it's very inefficient) and they are typically constrained by terrain. A good example is KTEX Telluride Regional Airport. It's on the east side of the valley at 9069 feet elevation. Remarks:  RY 09/27 RCMD TKOF RY 27; LAND RY 09 AND AVOID POPULATED AREAS. RY 09/27 GRADE -.08 ON RY ENDS, -1.3 TO APPROX MIDPOINT THEN +.75.

@Gerry Yes, same applies to e.g. Lukla airport with a mountain on one end. But I was under the impression the question was rather about "normal" runways.

For what it's worth, the soaring club at 69G Richmond Field usually uses 18 for glider launches and 36 for glider landings. Of course, if the wind is significant, then we do everything upwind.


text:
Linking equivalent airspeed with waypoints, altitude, time and speed
Say I want to find out EAS and I'm given a time that a pilot will reach a waypoint that is "X" Nautical Miles away, an altitude & I'm also given a ground speed that is increased by a tailwind. Is it possible to derive equivalent airspeed from these factors.
My current state of research is as follows:
I know the traditional EAS equation is useless in this case as I dont know the air density and other equations I've looked at require the Mach number which I also can't obtain. Basically all the EAS equations I've found require a density or the Mach number and I'm not sure how to proceed.

Is this a homework question? Can you specify the inputs you have more precisely?

How comes you don't know density and mach number? You have altitude, and then you either also have temperature, or assume standard temperature (both density and speed of sound depend on temperature, so you can't make any progress without it—different temperature, different answer).

It's not a homework question, it's a practise exam question. I'm given FL400, a waypoint that is 300NM away, with the pilot expected to arrive at the waypoint in 32 minutes. The aircraft ground speed is increased by a 100 knot tailwind.

I see two options. You can assume FL400 is also density altitude, or you can assume the standard temperature in tropopause and calculate the Mach number, because in practice anything that flies in FL400 maintains a Mach number. The difference is probably negligible, and you have to assume temperature either way.

Okay I see, I will attempt this and post my solution in the forthcoming days. Thank you for the help.

No, it is not possible to derive EAS from the data provided.

p=Actual density
p(o) = standard Sea Level Density
TAS = True Airspeed.

You can get to actual density from the pressure altitude and temperature (ISA+ or raw).  Without temperature, it is impossible to derive air density from pressure altitude; only estimates are possible.  For a more in depth derivation, this is a good source.


text:
Why do larger aircraft need two or more static ports?
Some background information:
"Static pressure is the measurement of the ambient barometric pressure at the aircraft’s CURRENT location AND CURRENT Altitude.
The Static Port is located in a position on the aircraft that will not be affected by air flow as the aircraft moves through the air. This is typically on the side of the fuselage but can also be on the back side of the Pitot Tube or any other number of locations, it varies by the aircraft. Again smaller aircraft will typically have one Static Port, larger aircraft with redundant systems will have two."
After reading through that paragraph, I am wondering as to why smaller aircraft typically have one static port, whilst larger aircraft have two or potentially more static ports.

Actually most smaller aircraft also have two, the other being pilot controlled and called "alt static" that provides an alternate static source (usually in cabin) when the external one gets plugged.

And some also have 3. My Cessna 177 has 3 ports, one in each side of the empanage and an alt-static port in the cabin.

You must add sources for your citation.

Trainers like my Cherokee save money by having a combined pitot/static vane. More capable aircraft often have redundant static ports—usually one on each side of the fuselage—because they fly in IFR weather. Often, aftermarket autopilots will have their own static port.

Your quote already answers your question:

larger aircraft with redundant systems will have two.

The key is redundancy. You want to have at least two independent systems to measure altitude and airspeed so if one fails, the other still provides good data. Of course redundancy is also a good thing in a small aircraft, but it always comes at a cost: complexity. With larger aircraft the added complexity and therefore maintenance cost does not make such a large difference any more therefore tipping the balance in favor of redundancy.
For passenger airliners with potentially hundreds of people on board, safety is far more important. They usually have even more than two static ports. E.g. the Boeing 737:

Air Data
The pitot static system is comprised of three separate pitot probes and six flush
  static ports. Two pitot probes and four static ports interface with the air data
  modules. The remaining auxiliary pitot probe and alternate static ports provide
  pitot and static pressure to the standby instruments. The auxiliary pitot probe is
  located on the first officer’s side of the airplane.
The air data modules convert pneumatic pressure to electrical signals and send
  these data to the ADIRUs. Each pitot air data module is connected to its on–side
  pitot probe; there is no cross connection. The air data module connected to the
  Captain’s pitot probe sends information to the left ADIRU, while the air data
  module connected to the First Officer’s pitot probe sends information to the right
  ADIRU. The remaining air data modules are located at the balance centers of the
  Captain’s and First Officer’s static ports. The air data module connected to the
  Captain’s static ports sends information to the left ADIRU, while the air data
  module connected to the First Officer’s static ports sends information to the right ADIRU.

(Boeing 737 NG FCOMv2 10.20.13 Flight Instruments, Displays - EFIS/Map System Description, emphasis mine)
This results in three independent measurements of altitude and airspeed:

Captain's side
First Officer's side
Standby Instruments

6 static ports, 5 AOA vanes, 4 fine stewards, 3 pitot tubes, 2 flaming fans, and a comfy fuselage! On the 7th day of ....


text:
Does a CFI need an Instrument Rating
https://www.ecfr.gov/cgi-bin/retrieveECFR?gp&n=14y2.0.1.1.2&r=PART#se14.2.61_1183
The or below is very confusing.  Doesn't it mean I need an Instrument rating or one of the things that follows it in the list?  Or means one or the other, not both.
Furthermore, when would one of the things that follows in the list NOT apply?
(2) An instrument rating, or privileges on that person's pilot certificate that are appropriate to the flight instructor rating sought, if applying for—
(i) A flight instructor certificate with an airplane category and single-engine class rating;
(ii) A flight instructor certificate with an airplane category and multiengine class rating;
(iii) A flight instructor certificate with a powered-lift rating; or
(iv) A flight instructor certificate with an instrument rating.

It is so unfortunate that the US gov / FAA can't author clear regulations.  Decades go by where this remains confusing, see below, some think yes, others think no.  If I have an instrument rating, it implies I have one of the other things it lists.  So, statong "An instrument rating, or" here adds nothing but confusion unless it IS required.  But if it IS required it should state AND not OR

I see what you mean. Everyone is convinced he's right, even though there are opposing opinions. It wouldn't be the US gov't if it was clear and obvious...

For most people, the answer is yes—you need an instrument rating to be a CFI or CFII for the categories that are listed.
It is possible to become an ATP by using military experience. In that specific case a person has instrument privileges but may not have an instrument rating.

Why do you believe that you need an ATP to be a CFI?

@RonBeyer You don’t need an ATP to be a CFI but if you have an ATP you meet the instrument requirement for CFI. As far as I know, the only way to become an ATP without having an instrument rating is to get an ATP based on military experience.

Right, so I'm not sure why you are talking about ATP at all? You don't need it to be a CFI, and you don't need an instrument rating to be a CFI either... You need one for ATP, but not all CFI's are on an ATP-track.

@RonBeyer For most people, to become a CFI in the categories listed in the question, you must have an instrument rating. The only exception that I know of is if you got your ATP through military experience and thereby skipped the normal CFI progression.

Maybe I'm confused, but you don't need to be a CFI to become an ATP either. ATP doesn't have anything to do with CFI, so I'm not sure why "getting your ATP through military experience" would have anything to do with CFI instrument rating?

@RonBeyer ATPL doesn't have an instrument rating per se; the confusing word in the CFI regs quoted is to account for the fact that ATPLs still have instrument privileges. But the only way to get an ATPL without first getting an instrument rating is via the military.

A CFI is required to have an instrument rating on their pilot certificate.  On the bottom of each FAR is citations pointing to the background and revisions of that regulation.
Here is the quote from 62 FR 16298

In proposed paragraph (c), the FAA added requirements for an applicant for a flight instructor certificate with a helicopter, airship, or powered-lift rating to hold an instrument rating. This was in addition to the existing requirement, which only specified that an applicant for a flight instructor certificate with an airplane or instrument rating hold an instrument rating on his or her pilot certificate.

The website ecfr.gov shows the reference as 62 FR 16220 but Cornell Law Website shows it as 62 FR 16298.  I don't know why the ECFR website is incorrect.

From 62 FR 40907

The FAA has clarified the eligibility requirement contained in paragraph (c)(2) for persons seeking a flight instructor certificate. Under new paragraph (c)(2), an applicant is required to hold either a commercial pilot certificate with an instrument rating or an ATP certificate with instrument privileges on that applicant’s pilot certificate that is appropriate to the flight instructor rating sought. The word ‘‘privileges’’ refers to the instrument privileges held by airline transport pilots.

This docket is from 1997.  How do we know there were other secret dockets published elsewhere?  The regs are the regs.  They are on ecfr.gov.  If something needs clarification, it should be updated in the regs, not secret pdfs from decades ago

Those dockets are the preamble to the regs.  It let's us know what the FAA was thinking as well as the industry through comments received by the FAA.  On the bottom of each reg it shows you where to find the preambles.  The regs were updated in 1997.  Tbat preamble is still valid today.

I like this answer, but the doc is so old and the wording is so different, I can't accept it.  I have no way of knowing the 1997 doc is legit, or that there's not some newer doc floating around.  Thanks.

You can search for the FR codes listed on the bottom of the regulation.  They are the research notes for the finished product.  I agree it should be plain language but the finished legalese is there for a purpose.

What they mean by that is if you hold an ATP - AIRPLANE SINGLE ENGINE, OR AIRPLANE MULTI-ENGINE, these certificates do not have instrument ratings associated with them, though you may serve as PIC on an IFR flight with an ATP ASE/AME. (you must hold an CPL ASEL/AMEL with an IA rating to apply for an ATP ASE/AME Certificate).  So you may apply for a flight instructor certificate if you have an ATPL only.

You do not need an instrument rating to become a Certified Flight Instructor, as the regulations you quoted state. You just have to be rated for the type in which you are instructing.


text:
IAP / "Instrument Approach Procedure (IAP) Charts" What does "Procedure NA" Mean?
The image below is of an FAA "Instrument Approach Procedure"
The entire thing is the "Procedure"
It contains a "Procedure Turn", which when not required typically states: "NoPT"
Now, in some places it states "Procedure NA" (red arrow near top) which seems to implicates the entire Procedure NOT the Procedure Turn.  However, the red arrow indication at top also seems to implicates the Procedure Turn because we're basically straight in from that location, so it wouldn't be needed, But again, NoPT would make more sense.  And why would the entire procedure be NA?
If we look at the two "Procedure NA" notes on the plan, then the entire "Procedure" would be NA from most approach directions.
So, Which is it?
Does "Procedure NA" mean The entire Instrument Approach Procedure?  or just the Procedure Turn?  If just the Procedure Turn, why does it use different vocabulary? Why not just say NoPT ?
Is there some other significance?
I looked in the chart user guide and can't find "Procedure NA" in it
Thanks

Although the wording on the chart is very confusing, it appears to indicate that you can not make a course reversal at the VORs themselves. Probably due to the congestion of the airspace and associated airways. This is only the case when using the VORs for navigation to the IAFs since neither of the VORs is an IAF. However, the IAP is an RNAV IAP. So, you can disregard the VORs and use GPS only to navigate to the IAFs as long as you stay above he 4200 foot Minimum Sector Altitude and cross the IAFs at or above 4400 feet. Beware of the higher terrain with MAximum Elevation Figures of 5600 and 6600 feet NNE of the IAP.
In other words, it means that the entire procedure is invalid if you are using VORs to navigate to the area in some circumstances. If you are coming from the North and West, you are required to use LEB. If you are coming from the South and East, you are required to use CON. If you are using GPS only, you are required to navigate to the IAFs directly (not necessarily Direct-to) using GPS and not VORs.

So you agree that it means "Procedure Turn", NOT "Procedure" ?

No, it means that the entire procedure is invalid if you are using VORs to navigate to the area in some circumstances. If you are coming from the North and West, you are required to use LEB. If you are coming from the South and East, you are required to use CON. If you are using GPS only, you are required to navigate to the IAFs directly (not necessarily Direct-to) using GPS and not VORs.

Not sure why you think the wording is confusing. I think it is quite clear, although my Jeppesen charts use a longer version: "Procedure not authorized for arrivals on LEB VOR airway radials R-117 clockwise R-199."

@Bianfable - Because, to someone not used to the area, stuck in the soup, and diverted to this IAP by ATC (not their original planned alternate), this may take a second or two of precious brain power to fully grasp. They may not be looking at their sectional or low enroute to know that the notes apply to the inbound airways. I had to pull up a sectional to see that. But, I am on the ground, relaxing with a cup of coffee. The longer note is one of the reasons I prefer Jepp, too.

What do you mean "If you are coming from the North and West, you are required to use LEB"  How do you determine that?  I could be coming from LEB via radar vectors right?  Then I'm not required to use LEB?  If so, then I'm still coming from that direction, (I'm in that range of radials) but now the procedure is NOT NA ?  Thanks

If you are coming from the North and West using VORNav, you would pass LEB to get to CON. In which case, that direction is unusable for CON for this IAP. You would have to VORNav to LEB if you are coming from that direction. If you are being Radar Vectored, you are not using VORNav to get to the IAP. The directions ACT gives you will then make the notes irrelevant. ACT will Radar Vector you to the IAP beginning at least at one of the IAFs.

Try drawing a magnetic deviation corrected compass rose with Magnetic North for each VOR. The unusable portion of LEB for the purposes of this IAP would be the arc from 117° to 199° going ClockWise. The unusable portion of CON for the purposes of this IAP would be the arc from 330° to 088° going ClockWise. You can not use this IAP if and only if you are using VORNav as navigation to the VORs on these radials.


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Possibility commuting using GA aircraft between rural towns?
Last week I went to visit my friend out in California City and noticed they do have an airport over there, so here is my idea.
Would it be practical to fly GA aircraft between California City and Los Angeles on a commuting basis, multiple times every week if not daily? Or generally commuting using aircraft in the rural area?
I know some areas in Alaska people doing exactly just this, but is this doable everywhere?

LA specifically could be hard to do. They are often cloud covered, making landing for small planes difficult.  Takeoff into zero-zero conditions is not something I would do, in case  you needed to make an emergency return landing. I would suspect LAX has high fees too. You might find other nearby airports more affordable.  I would imagine California City is almost always clear, being inland of the coastal mountains and on the edge of the Mojave.

As for the latter part of your question, is it doable everywhere, the answer would be a resounding no.
Unless you are a proficient IFR pilot, the climate would be one of the limiting factors in many places. For example where I live in, we have four seasons, of which the fall, with mostly IMC weather, lasts for about 6 months, leaving the other half of the year somewhat doable for a proficient VFR pilot. Now, I'm not kidding, it really is like that here: a couple of years ago it was cloudy (low level overcast) for three months in a row. Most of the cloudy days then were of the sort that would have made commuting under VFR very risky to say the least.
Another hurdle might be the cost. Again, as an example, where I live flying a private plane is ridiculously expensive. Even more so, if you want to hold an IFR -licence, which would be an absolute necessity if you wanted to commute by private plane here.
And one thing is scheduling. Unless you live and work very near an airport, you must consider transit times between your home, departure airport, destination airport and your workplace, and the other way around. Add half an our of flight preparation twice per day, and any time savings you might have thought of will quicky dissapear.
Generally I'd say it depends heavily on local conditions, but commuting by a private plane is (unfortunately) not a viable option everywhere. And I do not think it's a financially viable option anywhere...

This should be reasonably practical. For three years I have commuted daily in my Lancair from one urban SoCal airport to another, except for a couple of months when I was going to MHV every day instead. Very occasionally I'm forced to drive due to weather, airport/airspace closures or aircraft maintenance.


text:
Generally speaking, which assumes a greater (steeper) minimum climb or descent angle – approach procedures or departure procedures?
Generally speaking, which assumes a greater (steeper) minimum climb or descent angle – approach procedures or departure procedures?  Which would typically require a larger extent of airspace protected down to any given elevation (e.g. surface, 700' AGL, 1200' AGL, etc.)?
I'm specifically interested in how the FAA designs the protected airspace in the US, though I suspect the answer would be similar everywhere.

The descent is usually steeper, except in mountainous areas.
The standard descent angle is 3°, or about 300 feet per mile. Very few approaches are steeper than this; designers prefer to alter the lateral path instead, or just use high minimums.
The standard climb gradient is 200 feet per mile, or about 2°.  However, that can go up to 500 feet per mile, or about 5°, if terrain or obstacles dictate.
The discrepancy seems odd since runways are normally used from both ends, but in mountainous areas, it’s fairly common for there to be approaches to only one end.
Your question seems to assume airspace is protected based on the procedures, but it’s actually the opposite; they survey what terrain and obstacles exist, then design procedures to fit within the airspace that is protected.

So, if the arrival path is usually steeper than the departure path, do you have any thoughts on why the surface-level Class E "extensions" are sometimes called arrival extensions?  (Example -- https://aviation.stackexchange.com/q/91301/34686 )  It would seem that the departure procedures would be equally or more likely to merit an extra area of surface-level controlled airspace.

@quietflyer Approaches usually have long, flat segments before the FAF, and only the final segment will be steep, whereas a departure will usually be a continuous climb.

Thanks, that makes sense.


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Time of flying from Toronto to Philippines
Please I would
Like  to know how many hours I will be flying
Across the ocean . I will be flying on an aircraft 773 boing 777.

This looks like it would be better suited for Travel.SE.

If you know what you are flying on, then I assume you have your tickets. Every airline I've booked through gives some kind of estimate of the total flight time along with arrival and departure times.

@RonBeyer True, but I understand that the OP is interested in the time spent over the ocean, not the total flight time.

A direct flight from Toronto to Manila is about 16 hours. It is classified as a "Polar" flight and very little of it would be over the open ocean.
Depending on the weather and upper wind conditions, you would be initially flying either North East, or North West, from Toronto.
Most of the flight will be over land, with some of it over the frozen Arctic Ocean or Sea of Okhotsk near Russia.
FlightRadar24 PR119/PAL119


text:
Did NASA just broke the world record for fastest aircraft by going over 10 times faster than the previous record?
The current world record is held by the Lockheed SR-71 Blackbird. In 1976, this aircraft reached a top speed of 3,529.6 km/h, according to Wikipedia.
Fast forward 44 years, and NASA just launched the Perseverance mission to Mars, which includes the Ingenuity helicopter. This helicopter will perform the first extraterrestrial flight ever. In order to get to Mars, the rover and the helicopter will be accelerated to a relative velocity of 39,887.5 km/h (or 24,785 mph, according to SpaceFlightNow).
Even though Ingenuity is not reaching this velocity by means of its own propulsion, it is still an aircraft traveling at almost 40,000 km/h. So one could argue that it broke the speed record for fastest aircraft ever.
The Fédération Aéronautique Internationale set up specific rules for official aviation records. Will this one count?

This is ridiculous. The speed of about 40,000 km/h is reached by the rocket in space. Speed is relative in space, so you have to define with respect to what this speed is measured. You could define any arbitrary reference frame and reach arbitrarily high speeds (as long as they stay below speed of light). I highly doubt the Fédération Aéronautique Internationale will count this...

The Shuttle would have broken the SR-71 record by reaching orbital velocity, if "in space" counted.

SR-71 holds the record for the fastest air-breathing intra-atmospheric aircraft. However, the record for the fastest aircraft inside the atmosphere was the rocket powered X-15. Space is an entirely different thing. Even the International Space Station orbits at 17,100 mph (27,600 km/h)

We are all flying through space.

Doubtful. Aviation speed records are relative to the air or ground relative to the body they are flying. Ingenuity is currently a passenger on a spacecraft, it's not under its own power, it isn't flying and didn't do anything to get itself to the speed it is at. Once it is on Mars it will certainly be a record breaker, but that's when it's actually flying.


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What units are used for the horizontal grid lines on a sectional?
On a standard 1:500,000 aviation sectional chart, the map is broken down into quadrangle "sections" with a maximum elevation figure printed in blue in the center.
Using a chart-plotter I can see that the vertical (north-south) grid lines printed on the chart are in units of nautical miles.  Each quadrangle is 30 nautical miles vertically, and roughly 20.5 nautical miles wide (west-east).
What's confusing me is that the scale printed on the horizontal portion of the quadrangle section doesn't appear to be in nautical miles, statute miles, or even kilometers.  What does the horizontal scale represent?  Is there a unit associated with the horizontal grid?

quiet flyer's answer is really good. For further reading, you might want to google "WGS84" or check this: https://en.wikipedia.org/wiki/World_Geodetic_System

One tick mark along a horizontal grid line on a sectional chart denotes one minute of longitude. At the equator (but nowhere else), this is also equal to one nautical mile.  The further from the equator, the less the distance that is spanned by one minute of longitude.
One tick mark along a vertical grid line on a sectional chart denotes one minute of latitude, which is also equal to one nautical mile, anywhere on the earth's surface.
(The above comments assume a perfectly spherical earth.  Therefore they are not completely accurate, but they are close enough for nearly all aviation purposes.)
It is important to understand that at any given point on a sectional chart-- in fact, at ALL points on a sectional chart-- horizontal and vertical distances are portrayed at the same constant scale.  If you want to measure a given horizontal (or diagonal) distance in nautical miles, you can mark it off on a piece of paper and then hold it against the tick marks on a vertical grid line to get the distance in nautical miles.  Or you can just use a chart plotter.
For larger-area charts, it is necessary to vary the horizontal and vertical scales, to accomodate the curvature of the earth.

“horizontal and vertical distances are portrayed at the same constant scale”—within the limits of what is possible with a map projection. Good enough for a sectional chart, but not on larger area maps.


text:
how can someone view fuel shortage alerts?
Quoting https://www.kvue.com/article/news/local/new-jet-fuel-tanks-at-austin-airport-will-be-built-as-planned-after-split-council-vote/269-d7490d00-01f7-4330-9026-71f619f7ad8b ,

Airport leaders have issued 16 fuel shortage alerts since 2019, 11 of them last year. The alert is triggered when the current fuel supply drops below one day’s worth.

My question is...  how can one see fuel shortage alerts?
Would this be through a NOTAM or would you have to tune your radio to the CTAF frequency or whatever?

I think you may be caught by their use of the term "issued."  It implies there's some sort of broadcast or notification to the FAA.  I suspect this isn't the case at all, and by "issued" what they mean is the fuel supplier sent an email out to those with larger commercial accounts.  That might include a larger FBO, a charter operation, a regional airline contact...  But I suspect it's unlikely something a local or transient pilot will know without making a phone call to check on fuel status.  It would definitely not be a NOTAM, nor broadcast on a radio frequency.

@Max - I think in general you’re right. But I think it’s probably airport management that sends the email, not the fuel suppliers. And then, to whom do they send it?  Maybe the fuel suppliers to say, “Hey we need more fuel now and maybe to the airlines to say, “Be aware we might not have fuel for you when you get here”.

@Jim That hasn't been my experience.  Yes, on a small field in a small town, the airport manager might be the person who does everything, including managing fuel levels and calling for refills.  But in a typical mid-sized field the fuel vendor is just a tenant.  It would be much like a shopping mall manager monitoring the juice levels at Orange Julius, they're just not involved.  I don't buy my avgas from the airport, I buy it from the vendor, who has systems that forecast demand and electronically monitor fuel usage at the pumps.

@Max - you’re probably right, but I also think I’m thinking of “fuel suppliers” differently than you are. To me, fuel suppliers are the people that bring the fuel to the airport not the people who sell it there. It’s not Orange Julius it’s Sysco.


text:
Is there absolutely any way (hook or crook) to listen to ATC in India, especially Bangalore?
We can listen to various ATC radios across the world, but I really want to listen to the ATC at VOBL.

In principle you can listen to ATC of VOBL (Kempegowda International Airport, Bangalore) using a VHF air band radio receiver on the following frequencies:

Tower: 124.35 MHz
Ground: 121.65 MHz
Approach: 121.25 and 127.75 MHz

It is however illegal to own such a receiver in India:

Prohibition of possession of wireless telegraphy apparatus
  without licence.—Save as provided by section 4, no person shall
  possess wireless telegraphy apparatus except under and in accordance
  with a license issued under this Act.

(The Indian Wireless Telegraphy Act, 1933, emphasis mine)
There used to be coverage of Mumbai ATC on liveATC.net, but according to this thread on pprune.org it was shut down, presumably because it is illegal to pass on ATC transmissions in India.
See also:

Is it illegal for Joe Public to listen to ATC in the UK?

Surely other radio receivers are allowed to be owned by the general public though, such as an FM radio or UHF TV? What makes a radio that tunes to ~120 MHz special?

Receivers limited to only public spectrum operations would come with approval from some regulatory body (probably https://en.wikipedia.org/wiki/Wireless_Planning_%26_Coordination_Wing) to be allowed for use without a license.  Other receivers would not be so approved.

I am not a lawyer anywhere, but it would seem that wireless telegraphy would imply transmission capabilities. alternatly, is a pilot's use of the frequency spectrum part of the certificate or is it tied to the station built into the airframe?

Yes -- why would this law apply to something incapable of transmitting?

Transmission is not a requirement of "wireless telegraphy apparatus", which is a term of art: "wireless  telegraphy  apparatus’ means any apparatus, appliance, instrument or material used or capable of use in wireless communication, ..." (emphasis added). "Wireless transmitter" is a specific and separate term, so clearly transmission capability was contemplated as a subset of wireless telegraphy.


text:
How efficient would it be to have a plane with the cockpit in the back?
Would it be efficient to have a passenger planes cockpit move to the back of the plane, rather than the front? What I have in mind is cameras on the fuselage and nosecone that connects to the cockpit and give the pilot a wider viewpoint

How would that be better than sitting in the front from the get-go and doing away with, you know, the cameras and screens and such?

@JohnK I'm asking for a story I'm writing, though I won't go into details.

Welcome to aviation. SE! This question has some related information. It might help if you can tell us why you think it could be more efficient.

Science fiction?

@JohnK Based entirely on real-world science, though it is a dystopian future

@JohnK I wouldn't be asking the question if it were science fiction

Well you could have the plane as more or less an autonomous drone with a compartment in the back where a human "minder" pilot is there for emergencies to land it of the drone goes haywire, relying on 3D cameras.

What do you mean by "efficient"?

I initially interpreted "efficient" as suggesting that a rear cockpit would be close to the tail control surfaces and no farther away from the wings and engines, so all the control lines etc. would be shorter.  It would be nice to have clarification of what that word actually means in this question.

He's writing fiction and needs to know if there are any efficiency advantages to such a configuration, that would make a fictional aircraft designed like that technically plausible to the reader, because that configuration is necessary to the plot line.

Perhaps he was inspired by the Thunderbird's Fireflash, with the cockpit in the vertical stabiliser? https://youtu.be/s1jrIbXTnak

This adds way too much complication. Just do away with all the complicated stuff

You mean like this one: https://en.wikipedia.org/wiki/Gee_Bee_Model_R  The only real advantage seems to be that you can hang a great big radial engine on the front :-)


text:
Does it make sense to say an aircraft has an attitude of 3° or that it has a flight position of 3°?
I am trying to translate an aircraft manual, and there is a diagram showing what the HUD would look like given a "posición de vuelo de 3°".
The diagram is captioned in Spanish as "vuelo horizontal a 3° de posición de vuelo".
I'm thinking  of two ways to translate this, but I think both do not completely make sense, and I think they don't make sense because the original is using terminology in an imprecise way.
If I translate it as "Level flight at 3° flight attitude", it seems off because attitude is a combination of both pitch and roll, so how could you have an attitude of 3°?
If I translate it as "Level flight at a flight position of 3°", then it seems even more off because flight position, as I understand it, is combination of all 3 angles of orientation, yaw, pitch and roll. So you can't just say "my flight position is 3°"
So I am basically writing to confirm my suspicion that this doesn't really make sense and that the diagram is more likely referring to an elevation/pitch of 3° (with respect to the fuselage reference line). If anyone knows Spanish and is familiar with the term "posición de vuelo", then that's a bonus :)

Probably 3 degrees nose up.  Show us a picture of the HUD and most of us will understand without knowing Spanish.

Actually most of the time when referring to "attitude" we are talking only about pitch attitude.  You can call bank angle "roll attitude" but it's more typically called "bank angle" in common usage.   If I have an airplane in a turn and I'm descending, you can just say my attitude is too low and I need to raise it, and I won't be confused as to whether you're referring to pitch or roll and will know I need to increase pitch attitude.
So 3 degrees of flight attitude would clearly, to me at least, refer to flight with the airplane's pitch attitude 3 degrees above the horizon while in level flight (or turning for that matter), not climbing or descending, which sounds like a pretty typical number.

You include the perfect translation in your answer: "pitch attitude".

What about "flight position" then? Would it have the same meaning as "attitude"?

Yes that's how I would interpret flight position.

You would have to be a little more specific as attitude is defined in terms of angles in both bank and pitch (angular movement about the longitudinal and lateral axes of the aircraft relative to the datum of the horizon).  You would usually specify bank attitude in terms of an angular displacement as well as indicate whether the aircraft is banked left or right.  Pitch attitude would be similar with an angular displacement from the horizon and an indication whether it was nose up or nose down.  For example, you might say “20° left bank and 10° pitch nose up”.

It is the" flight path is leveled but the attitude (of the  nose) is up 3 degrees  " to maintain the level flight at the specific speed .If will be below 3 degrees nose up then a/c glide slope is under the level of the horizontal line so the a/c will descend from the level flight pattern.


text:
How do SIDs work in New York City?
I've started working to make airport files for an online ATC game, and my first airport is Newark Liberty (DP: https://flightaware.com/resources/airport/KEWR/DP/all/pdf).  What I already understand is that there are various climbs valid for different runways, and that the SID directs each aircraft to its first fix.  What I don't understand is how the climb is determined for each aircraft.  I also want to know how often airplanes use the SIDs, as I sometimes see planes on Flightradar not following the climb paths.
Thanks, this has confused me for a week or two.

If you ask how steep is the climb then it is according to airplane/aviation company guides. Often this is derived from minimum flight time.

The LIB4 and EWR4 SIDs, and others like them with just a bunch of VORs, are designed to give ATC maximum flexibility and assume radar vectors. Basically, you take off, make a turn or two to get clear of the airport (and any low obstacles), and then ATC will vector and climb you based on conflicts with other planes at that moment, so you'll probably never get the same instructions twice. There is no real plan; it's literally made up on the spot by each controller for each plane.
The PORTT4 (RNAV) SID is completely different: you have various specific routes to follow and detailed climb plans for each. Many such arrivals and departures in an area will be carefully designed to never conflict with each other (the top and bottom altitudes listed usually indicate there's another SID/STAR crossing 1000ft above/below at that point), so ATC just watches to make sure everyone follows the plan—and gives out shortcuts when possible. Unfortunately, that SID is only valid for two of the six runways, though presumably they're the ones used most often.
Note the latter's lost comms procedure is just to follow the charted plan you're expecting to follow anyway, though without any shortcuts, whereas the former has an entirely different (and uncharted) plan that you'd probably never follow otherwise.

The various climbs are usually determined by noise abatement interests and other stakeholders. You will find that some departures can be quite complex.
I cannot say anything to aircraft, that don’t follow the SIDs, they are there for a reason. Maybe those are aircraft at cruising altitude passing over the aerodrome?

I think that especially in the US it used to be common to receive radar vectors (ATC telling aircraft where to head) instead of following published procedures, but not sure how it works these days. Additionally, aircraft might request to turn off the standard routes to avoid weather (mostly thunderstorms). These all might account for aircraft climbing off the SIDs.

The climb on a SID is determined based on the minimum climb needed to clear obstacles in the departure as well as aircraft performance.  Passenger comfort also comes into play.  Typically a pilot will follow at least the minimum requirements published on a SID unless otherwise directed by ATC.  If a pilot’s aircraft cannot match the performance requirements of the SID, they should notify ATC prior to departure that they are unable and request a different DP their aircraft can comply with.
SIDs are created by the FAA or the individual operators and used by aircraft departing from airports to streamline the flow of traffic departing that location to their transition into the enroute structure ie establishing on low or high altitude airways.  For heavy transports departing busy airports, a SID or an OCD will almost always be used.  Light aircraft ie GA reciprocating and non transport category turboprops may make use of a SID - though some SIDS are restricted to turbojet aircraft only - and, at a bare minimum, a OCD is recommended in the case of marginal weather.  Pilots operating in IFR may opt out of flying a SID by placing a “no SID” comment in the remarks section of their IFR flight plan.


text:
Why are some points shown on a STAR but not attached to the route?
I'm looking at the SERFR4 arrival into San Francisco.  There's two waypoints, STOKD and MAKRS, which are shown on the plate but aren't actually connected to the route.  Can anyone help explain why they're there, as there's no mention of either elsewhere in the route.  Thanks!
SERFR4 Arrival: https://flightaware.com/resources/airport/SFO/STAR/SERFR+FOUR+(RNAV)/pdf

If it's printed on the chart, then ATC doesn't need to spell it out if they want to send you there for some reason?

Coming from Southern California, you'll often be filed to one of those points, and then on to SERFR for that arrival.  Putting those two points on the page gives perspective of what direction one is coming in from.
It's all RNAV stuff, so is having them on the chart strictly necessary in order to navigate? No.  But it gives a little bit of a picture of what you're expecting to see on the Navigation Display.
Also, as mentioned in the comment, if ATC needs to reroute somebody off of what they filed & over one of those points & then to SERFR, having the point on the page may reduce copying errors when the controller spells out "cleared direct MAKRS, Mike Alpha Kilo Romeo Sierra" -- it at least gives the pilot something to reference when that clearance is being read to him.  Things that reduce the frequency congestion ("Was that Mike Kilo Alpha Romeo Sierra? I don't have that in the database..." "No, it's Mike Alpha Kilo Romeo Sierra" "Oh, okay, Mike Alpha Kilo Romeo Sierra, we'll use that.") are beneficial.

To your first point it's interesting to note that STOKD is on the high altitude chart and MAKRS is on the low with STOKD marked as a reporting point.  They both are also on the boundary between LA Center and Oakland Center, so you'd be getting an ATC handoff at those fixes.


text:
Does an Airbus FAP display any indication of a full waste tank?
I have doubt about controls on FAP regarding Waste Tank.
I understand when crew person clicks on Input On button, FAP displays the quantity of Water and Waste tank.
But what happens when Waste Tank is Full?
When waste tank is full, Will FAP displays any indication upfront or Flight attendant has to click on Input on Button to know the quantity?

resources location are usually considered as off-topic here. You may ask a question such that answer should include technical manuals and other resources you may find useful for further reading.

@ManuH I think it's fine now after ymb1's edit.